I have sharpened many a tool over my days, but my best methods have been with my hand. I haven't found the perfect tool for sharpening yet.
Now, I have seen quite a few tools (I just haven't had the opportunity to use them myself). Here is one that is made in Russia, and I have talked to the owner of the company several times. Here is their website
http://new_2.tsprof.com/en/ The only thing bad is that I don't have around 400 dollars to drop on a sharpening system. I have no doubt that someone could use this system and create a sharpening company. One revenue source would be quilt shows. There's usually a single guy who sharpens scissors for the quilters, and he often has a backorder for weeks. Now, I have never sharpened scissors or anything else with this unit, but I imagine that it would create fantastic results.
Here's a youtube video where Wranglerstar shows off the little russian sharpening system. [youtube]https://www.youtube.com/watch?v=k3SbEWFSA8[/youtube]
As for any manual sharpening, I would refer to Mr Bernie Weisgerber. His sharpening work is featured in this forest service video. He is fun to watch, and gives a great amount of information. [youtube]https://www.youtube.com/watch?v=22tBYD-HMtA[/youtube]
For my own hand sharpening, I use two tools that are efficient and cheap. I use a Lansky Puck (
https://www.amazon.com/Lansky-Puck-Multi-Purpose-Sharpener-Blade/dp/B000B8FW0Y), and a Lansky Blademedic (
https://www.amazon.com/Lansky-3143-PS-MED01-BladeMedic/dp/B0085PPSIQ). I have found that the blademedic produces superior edges, and with some proficiency I can get shave sharp edges on nearly every blade (even my axes) with the blademedic. The trick with the blademedic is that you need to keep your blade perpendicular to the tool, so that it cuts at the same angle. I've found that the carbide and ceramic "V" sharpeners are all that I need to get that razor sharp edge on a tool. For axes and machetes, I lay the tool down with the blade up, and run the blade medic over the blade. The Blademedic is just long enough to where I don't worry about cutting myself (but I would always suggest gloves in this sharpening configuration). The carbide sharpener is VERY aggressive, so I only use that at the very beginning .... and I must stress how important it is to keep your eye on the gap between the tool and the blade. You want to keep the word "CERAMIC" parallel to the side of the blade. It's very easy to angle up or down as you sharpen a larger tool, but the solution is simple. MIND THE GAP!!! Do that, and you will get a sharp blade. Keep watching the gap all of the way to the end of the blade, and you will feel those sharpening rods working.
Also, I don't ever use oil on my stones. Once you start with oil, you have to keep using oil. I just use a tiny bit of water! Some people enjoy taking the puck out into the field, but I've found it to be a bit large and dangerous when compared to the Blademedic. Due to it's design, your fingers are in jeopardy when sharpening any object, and it's sort of a large cumbersome shape. The blade medic fits into my pocket much easier, and it makes me feel as though my fingers are safer. Also, you don't use water for the Blademedic (another plus in the brush). I have used nearly ever whetstone available to sharpen my pocket knives.
If you're looking for a traditional hand sharpen, the diamond grit sharpener from harbor freight is a great value.
https://www.harborfreight.com/4-sided-diamond-hone-block-92867.html It costs under 15 dollars, and you get 4 different grits for sharpening. Each side has metal with diamond grit encrusted on it. You can see the different colored shapes on each side, but that is not where sharpening happens. Those cutouts help you know which grit you are working on, but they are there to allow for the dispersal of material to come off your blade, but also for the diamond sharpening material to come off of the block. Both get worn off .... heck, it's a cheap sharpener - so it won't last forever.
For me, the all around winner is the blademedic. I can sharpen anything, pack it anywhere, and it's cheap.